\begin{tikzpicture}
    \tkzDefPoints{0/0/C, 3.5/0/B, 2.5/0/D,  1.5/2/A}

    \tkzDrawSegments(C,B)
    \tkzDrawPoints[fill=black](A,D)

    \tkzLabelPoints[below](B,C,D)
    \tkzLabelPoints[above](A)
\end{tikzpicture}

